Bladder Outlet Obstruction Rats Research Articles

Protective effect of equol intake on bladder dysfunction in a rat model of bladder outlet obstruction.

This study evaluates the impact of equol, a metabolite of soy isoflavone, on bladder dysfunction in rats with bladder outlet obstruction (BOO). In addition, we investigate its potential as a neuroprotective agent for the obstructed bladder and discuss its applicability in managing overactive bladder (OAB). Eighteen male Sprague-Dawley rats were divided into three groups (six rats per group) during the rearing period. The Sham and C-BOO groups received an equol-free diet, while the E-BOO group received equol supplementation (0.25 g/kg). At 8 weeks old, rats underwent BOO surgery, followed by continuous cystometry after 4 weeks of rearing. The urinary oxidative stress markers (8-hydroxy-2'-deoxyguanosine and malondialdehyde) were measured, and the bladder histology was analyzed using hematoxylin-eosin, Masson's trichrome, and immunohistochemical staining (neurofilament heavy chain for myelinated nerves, peripherin for unmyelinated nerves, and malondialdehyde). Equol reduced BOO-induced smooth muscle layer fibrosis, significantly prolonged the micturition interval (C-BOO: 193 s, E-BOO: 438 s) and increased the micturition volume (C-BOO: 0.54 mL, E-BOO: 1.02 mL) compared to the C-BOO group. Equol inhibited the increase in urinary and bladder tissue malondialdehyde levels. While the C-BOO group exhibited reduced peripherin alone positive nerve fibers within the smooth muscle layer, equol effectively attenuated this decline. Equol reduces lipid peroxidation and smooth muscle layer fibrosis in the bladder and exhibited neuroprotective effects on bladder nerves (peripheral nerves) and prevented the development of bladder dysfunction associated with BOO in rats. Consumption of equol is promising for the prevention of OAB associated with BOO.

Is bladder outlet obstruction rat model to induce overactive bladder (OAB) has similarity to human OAB? Research on the events in smooth muscle, collagen, interstitial cell and telocyte distribution

BackgroundCellular and cytoskeletal events of overactive bladder (OAB) have not been sufficiently explored in human bladder due to different limitations. Bladder outlet obstruction (BOO) had been induced in different animal models with different methods to induce (OAB). Similarity of the animal models of BOO to the human OAB is postulated but has not been confirmed. The interstitial cells of Cajal (ICCs), and telocytes (TCs) are an important players in smooth muscles conductivity, they had not been well investigated in the previous BOO models. Objectives are to investigate the morphological pattern of cellular, cytoskeleton and telocytes distribution in BOO rat model and to match the events in two time periods and compare it to the findings in real-world human OAB.MethodsFemale Sprague-Dawley rats (Rattus norvegicus) were randomly divided into: sham (n = 10), BOO 6 W (n = 10), BOO 8 W (n = 10). Operative procedure to Induce BOO was done under anesthesia with intraperitoneal Ketamine administration. The Effect of induction of BOO was evaluated after 6 and 8 weeks. The rats were anesthetized, and the urinary bladder was removed, while the rat was unconscious under anaesthesia it was transferred to the inhalation anaesthesia cage for euthanasia, rats were sacrificed under light anesthesia using isoflurane. Care of animals, surgical procedure, and euthanasia adhered to Guide for the Care and Use of Laboratory Animals, and AVMA Guidelines for the Euthanasia of Animals. The retrieved bladder was processed for examination with histopathology, immunohistochemistry (IHC), and transmission electron microscopy (EM).ResultsHistological examination of the bladder shows thinner urothelium, condensation of collagen between muscle bundles. IHC with c-kit shows the excess distribution of ICCs between smooth muscle bundles. EM shows frequent distribution of TCs that were situated between collagen fibers. Finings in BOO 6 W group and BOO 8 W group were comparable.ConclusionThe animal model study demonstrated increased collagen/ smooth muscle ratio, high intensity of ICCs and presence of TCs. Findings show that a minimally invasive procedure to induce BOO in rats had resulted in an OAB that has morphological changes that were stable in 6 & 8 weeks. We demonstrated the distribution of TCs and ICCs in the rat animal model and defined them. The population of TCs in the BOO rat model is described for the first time, suggests that the TCs and ICCs may contribute to the pathophysiology of OAB. Similarity of animal model to human events OAB was demonstrated. These findings warrant further study to define the role of TCs in OAB.Clinical trial registryThe study does not require a clinical trial registration; it is an experimental animal study in basic science and does not include human subjects.

Survivin knockdown alleviates pathological hydrostatic pressure-induced bladder smooth muscle cell dysfunction and BOO-induced bladder remodeling via autophagy.

Aim: Bladder outlet obstruction (BOO) leads to bladder wall remodeling accompanying the progression from inflammation to fibrosis where pathological hydrostatic pressure (HP)-induced alteration of bladder smooth muscle cells (BSMCs) hypertrophic and excessive extracellular matrix (ECM) deposition play a pivotal role. Recently, we have predicted survivin (BIRC5) as a potential hub gene that might be critical during bladder fibrosis by bioinformatics analyses from rat BOO bladder, but its function during BOO progression remains unknown. Here, we investigated the role of survivin protein on bladder dysfunction of BOO both in vitro and in vivo. Methods: Sprague-Dawley female rats were divided into three groups: control group, BOO group, and BOO followed by the treatment with YM155 group. Bladder morphology and function were evaluated by Masson staining and urodynamic testing. To elucidate the underlying mechanism, hBSMCs were subjected to pathological HP of 200cm H2O and co-cultured with the presence or absence of survivin siRNA and/or autophagy inhibitor 3-MA. Autophagy was evaluated by the detection of Beclin1 and LC3B-II expression, proliferation was conducted by the EdU analysis and PCNA expression, and fibrosis was assessed by the examination of Col 1 and Fn expression. Results: BOO led to a gradual alteration of hypertrophy and fibrosis of the bladder, and subsequently induced bladder dysfunction accompanied by increased survivin expression, while these histological and function changes were attenuated by the treatment with YM155. HP significantly increased survivin expression, upregulated Col1 and Fn expression, enhanced proliferation, and downregulated autophagy markers, but these changes were partially abolished by survivin siRNA treatment, which was consistent with the results of the BOO rat experiment. In addition, the anti-fibrotic and anti-proliferative effects of the survivin siRNA treatment on hBSMCs were diminished after the inhibition of autophagy by the treatment with 3-MA. Conclusion: In summary, the upregulation of survivin increased cell proliferation and fibrotic protein expression of hBSMC and drove the onset of bladder remodeling through autophagy during BOO. Targeting survivin in pathological hBSMCs could be a promising way to anti-fibrotic therapeutic approach in bladder remodeling secondary to BOO.

Inhibitory effects of vibegron, a β3-adrenoceptor agonist, on the myogenic contractile and mechanosensitive afferent activities in an obstructed rat bladder

To determine the role of β3-adrenoceptor agonists on bladder sensory facilitation related to bladder myogenic contractile activities in bladder hyperactivity, we investigated the effects of vibegron, a β3-adrenoceptor agonist, on the bladder and sensory function by evaluating cystometry and mechanosensitive single-unit afferent activities (SAAs), respectively, in a male rat model of bladder outlet obstruction (BOO).BOO was created by partial ligation of the urethra. Ten days after the surgical procedure, cystometric and SAA measurements were taken under two distinct conditions: a conscious-restrained condition, in which the bladder was constantly filled with saline, and a urethane-anesthetized condition involving an isovolumetric process with saline. For each measurement, vibegron (3 mg/kg) or its vehicle was administered intravenously after the data were reproducibly stable. In addition, the expression of β3-adrenoceptor and substance P (SP), a sensory neuropeptide, in the bladder was further evaluated following immunohistochemical procedures.Number of non-voiding contractions (NVCs) in cystometry was decreased after vibegron-administration, which was a significant change from vehicle group. Number of microcontractions and SAAs of Aδ- and C-fibers were significantly decreased by vibegron-administration. Furthermore, β3-adrenocepor and SP were co-expressed in the suburothelium layer of the bladder.These findings indicated that vibegron showed inhibitory effects on NVCs and microcontractions of the bladder, and SAAs of the Aδ- and C-fibers in BOO rats. The study suggested that vibegron can partly inhibit the mechanosensitive afferent transduction via Aδ- and C-fibers by suppressing bladder myogenic contractile activities in the rat bladder hyperactivity associated with BOO.

Human amniotic fluid stem cells can alleviate detrusor dysfunction caused by bladder outlet obstruction in rats

The present study examined whether bladder detrusor dysfunction due to partial bladder outlet obstruction (pBOO) could be improved after the treatment of human amniotic fluid stem cells (hAFSCs). 72 female rats were grouped into sham operation, pBOO, and pBOO with hAFSCs treatment (pBOO + hAFSCs) for in vitro and in vivo studies. Bladder weight, bladder wall thickness, the ratio of collagen to smooth muscle and the levels of positive CD11b/c and HIS48 cells was significantly increased after pBOO but improved after hAFSCs treatment. Cystometries showed impaired bladder function after pBOO. Protein and mRNA levels of hypoxia inducible factor-1α, CCL2, interleukin-1β, transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), α-smooth muscle actin, collagen I and collagen III were increased at 2 and/or 6 weeks, but proteins and mRNA expressions of protein gene product 9.5 were decreased at 2 and 6 weeks after pBOO. These abnormalities were improved after hAFSCs treatment. The expressions of TGF-β1 and CTGF in cultured detrusor cells of pBOO rats were increased but were improved after hAFSCs treatment. The present results showed hAFSCs treatment could improve bladder detrusor dysfunction in pBOO rats, which may be related to the reduction of inflammatory and pro-fibrotic markers in detrusor muscle cells.

Human Urine-Derived Stem Cells Improve Partial Bladder Outlet Obstruction in Rats: Preliminary Data and microRNA-mRNA Expression Profile

Partial bladder outlet obstruction (pBOO) often results in bladder tissue inflammation and remodeling. As human urine-derived stem cells (USCs) have demonstrated therapeutic benefits, we used a rat model to investigate the effect of USCs on bladder function and explore the miRNA and gene expression profiles in bladder tissue using RNA sequencing. Eighteen rats were assigned to a sham surgery group, pBOO group, and pBOO+USC group (six biweekly treatments). Routine urodynamic monitoring, analysis of detrusor muscle strips, and pathophysiology assessments were conducted. Finally, altered miRNA and mRNA expression profiles of bladder tissue were examined using RNA sequencing and bioinformatics analysis. After USC treatment, elevated bladder compliance and maximal voiding pressure, declined end filling pressure and voided volume, and improved detrusor muscle contractility and carbachol sensitivity were found. Histology and TUNEL assay revealed reduced collagen deposition and muscle cell apoptosis in bladder tissue. The differential expression of eight miRNAs was reversed by USC treatment. Two large nodes (miR-142 and miR-9a) were identified in the miRNA-gene interaction network in the USC-treated group. The Kyoto Encyclopedia of Genes and Genomes analysis revealed enrichment of multiple significant pathways, including those involved in necroptosis and cytokine-cytokine receptor interactions. This is the first study to demonstrate the protective effect of USCs on bladder function and remodeling in pBOO rats. The miRNA and mRNA expression levels differed in the bladder of pBOO rats with and without USC treatment. Although the mechanism underlying these effects has not been fully elucidated, necroptosis and cytokine-cytokine receptor interaction-related pathways may be involved.Graphical abstract

Pathophysiology and pharmacotherapy of benign prostatic disorders

Men with benign prostatic hyperplasia (BPH) often experience symptoms of overactive bladder (OAB), and bladder outlet obstruction (BOO) is one of cause of BPH. It has been suggested that bladder myogenic microcontractions or micromotions may partly contribute to the development of urgency (bladder sensory (afferent) hypersensitivity) in OAB related to BOO. We have investigated the direct effects of drugs (β3-adrenoceptor agonists, α1-adrenoceptor antagonists, PDE type5 inhibitors) on the bladder afferent function in BOO rats. In our results, almost all drugs may act on the bladder afferent function, and mirabegron inhibits the afferent activities through the suppression of the bladder myogenic microcontractions in BOO condition. Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) causes long-standing pain and/or storage symptoms including storage symptoms, such as urgency and frequency. We evaluated the likelihood of deterioration of bladder sensation in a carrageenan-induced CP/CPPS model. In results, the carrageenan-induced CP/CPPS rat model showed edema, ischemia, and inflammatory pain in the prostate, whereas a little change was detected in bladder sensation. These findings demonstrated that the bladder sensation is unlikely deteriorated in this model, suggesting CP/CPPS is possibly overlapping with symptoms in BPH.

Improved bladder contractility after transplantation of human mesenchymal stem cells overexpressing hepatocyte growth factor into underactive bladder from bladder outlet obstruction models of rats.

IntroductionAn underactive bladder can lead to difficulty in voiding that causes incomplete emptying of the bladder, suggesting the need for a new strategy to increase bladder contractility in such patients. This study was performed to investigate whether human mesenchymal stem cells (hMSCs) were capable of restoring bladder contractility in rats with underactive bladder due to bladder outlet obstruction (BOO) and enhancing their effects by overexpressing hepatocyte growth factor (HGF) in hMSCs.Materials and methodsThe hMSCs were transplanted into the bladder wall of rats. Fifty female Sprague-Dawley rats at six weeks of age were divided into five groups: group 1: control; group 2: sham intervention; group 3: eight-week BOO; group 4: BOO rats transplanted with hMSCs; and group 5: BOO rats transplanted with hMSCs overexpressing HGF. Two weeks after the onset of BOO in groups 4 and 5, hMSCs were injected into the bladder wall. Cystometry evaluation was followed by Masson’s trichrome staining of bladder tissues. Realtime PCR and immunohistochemical staining were performed to determine for hypoxia, apoptosis, and angiogenesis.ResultsCollagen deposition of bladder increased in BOO but decreased after transplantation of hMSCs. The increased inter-contraction interval and residual urine volume after BOO was reversed after hMSCs transplantation. The decreased maximal voiding pressure after BOO was restored by hMSCs treatment. The mRNA expression of bladder collagen1 and TGF-β1 increased in BOO but decreased after hMSCs transplantation. The decrease in vWF-positive cells in the bladder following BOO was increased after hMSCs transplantation. Caspase 3 and TUNEL-positive apoptosis of bladder cells increased in BOO but decreased after transplantation of hMSCs. These effects were enhanced by overexpressing HGF in hMSCs.ConclusionTransplantation of hMSCs into bladder wall increased the number of micro-vessels, decreased collagen deposition and apoptosis of detrusor muscle, and improved bladder underactivity. The effects were enhanced by overexpressing HGF in hMSCs. Our findings suggest that the restoration of underactive bladder using hMSCs may be used to rectify micturition disorders in patients following resolution of BOO. Further studies are needed before hMSCs can be used in clinical applications.

Upregulation of AQP2 mediated by transcription factor FOXO1 inhibits TGF-β-induced fibrosis in human urothelial cells.

Bladder outlet obstruction (BOO) is a common urological disease, and inhibition of TGF-β-induced bladder tissue fibrosis may serve as an alternative strategy for BOO treatment. Aquaporin (AQP)2 was reported to be aberrantly expressed in rat BOO, but its specific role was not clarified. The aim of the present study was to explore the role of AQP2 in TGF-β-induced urothelial cell fibrosis and elucidate the potential underlying mechanism. The SV-HUC-1 human urinary tract epithelial cell line was treated with TGF-β1 to establish an in vitro model of bladder fibrosis. Cell Counting Kit-8 and wound healing assays were performed to measure cell viability and migration, respectively. Cell transfection was conducted to silence/overexpress AQP2 and Forkhead box O1 (FOXO1). Protein expression was measured using western blotting. Luciferase reporter and chromatin immunoprecipitation assays were used to verify the predicted interaction between AQP2 and FOXO1. The present study found that AQP2 expression was downregulated in TGF-β1-treated urothelial cells. Overexpression of AQP2 significantly suppressed cell viability, migration and epithelial-to-mesenchymal transition in TGF-β1-treated SV-HUC-1 cells. In addition, FOXO1 overexpression exerted similar effects as AQP2 overexpression on TGF-β-treated SV-HUC-1 cells, but these changes were partially abolished by AQP2 knockdown. It was also found that FOXO1 was able to bind to the AQP2 promoter and regulate AQP2 expression. In conclusion, the transcription factor FOXO1 may upregulate AQP2 expression, thereby inhibiting TGF-β-induced fibrosis in human urothelial cells. The findings of the present study may provide a novel potential strategy for the clinical treatment of BOO by targeting AQP2.

The roles of MCP-1/CCR2 mediated macrophage recruitment and polarization in bladder outlet obstruction (BOO) induced bladder remodeling

Bladder outlet obstruction (BOO) can lead to alternation of bladder structure and function, known as bladder remodeling. Macrophage is a heterogeneous cell type and implicated in immunity regulating and tissue repairment. The relationship between macrophage and BOO remains unclear. We determined the pivotal role of macrophage recruitment and polarization in bladder remodeling. Sprague-Dawley rats underwent surgical operation of a BOO for either 1, 3, 6 weeks and were compared with sham-operated rats. The BOO rats in the experimental group were orally administrated with 5 mg/kg RS-504393, a C-C chemokine receptor (CCR2) antagonist, for 6 weeks, and the rats in the control group were treated with vehicle. Bladder tissues were harvested for assays of flow cytometry, quantitative reverse transcription polymerase chain reaction, histological examinations, immunohistochemistry staining and immunofluorescence. After induction of BOO, M1 macrophages were predominantly observed at inflammatory stage while M2 macrophages were mainly found during fibrosis stage. Flow cytometry analysis revealed that the ratio of M1/M2 significantly increased at 3 weeks (P = 0.0013) when compared to the sham-operated group. Interestingly, our results showed that M2 macrophages promoted BOO-induced fibrosis through indirectly secreting TGF-β and directly transforming to collagen-producing myofibroblast. Additionally, RS-504393 treatment significantly decreased the number of M1 and M2 macrophage infiltration in bladder tissue, and bladder fibrosis was attenuated by RS-504393 treatment compared with that in the vehicle-treated rats. In summary, macrophages play a pivotal role in bladder remodeling and targeting MCP-1/CCR2 signaling pathway might be a therapeutic strategy for human bladder fibrosis.

The effect of testosterone replacement therapy on bladder functions, histology, apoptosis, and Rho-kinase expression in bladder outlet obstruction and hypogonadism rat model

Background/aimThe effect of testosterone replacement therapy was investigated on bladder functions, histology, apoptosis as well as Rho-kinase expression in the rat bladder outlet obstruction (BOO) and hypogonadism models. Materials and methods30 mature male rats divided into 4 groups: sham group (n = 8), BOO group (n = 8), BOO + orchiectomy group (n = 7), BOO + orchiectomy + testosterone (T) treatment group (n = 7). Cystometric findings, apoptosis index, Rho-kinase (ROCK-2) expression, and smooth muscle/collagen ratio were compared. Results BOO did not change ROCK-2 expression level, compared to sham group (P > 0.05). However, when compared to BOO group (P < 0.01), BOO + orchiectomy led ROCK-2 increase. The testosterone treatment failed to reverse the up-regulation of ROCK-2 induced by orchiectomy although it tended to lower ROCK-2 level. Compared to sham group (P = 0.002), changes in maximal bladder capacity and leak point pressure were higher (P = 0.026, P = 0.001), and bladder compliance was lower in BOO group. Also, the apoptosis index was different between the two groups (P = 0.380). Smooth muscle/collagen ratio was higher in BOO + orchiectomy + T group than in BOO + orchiectomy group (P = 0.010).ConclusionsThe research draws attention to alternating treatment approaches in case of the presence of hypogonadism and BOO.

The role of interleukin-6/interleukin-6 receptor signaling in the mechanical stress-induced extracellular matrix remodeling of bladder smooth muscle

Extracellular matrix (ECM) remodeling is strongly associated with pathological changes induced by bladder outlet obstruction (BOO). In this study, we investigated the role of interleukin-6 (IL-6) in mechanical stretch-induced ECM remodeling of bladder smooth muscle. To construct a BOO animal model, the urethras of female Sprague–Dawley rats were partially ligated. In addition, increased hydrostatic pressure and mechanical stretching were applied to human bladder smooth muscle cells (HBSMCs) as an in vitro model. The expression of rat inflammatory genes was analyzed using DNA microarrays. We used quantitative RT-PCR (qRT-PCR) and immunohistochemical staining to detect IL-6 in the bladder smooth muscle of rats. To determine the specificity of IL-6, small interfering ribonucleic acid (siRNA) transfection and IL-6 receptor inhibitor (SC144) were applied to HBSMCs. qRT-PCR with siRNA transfection was also used to determine the specificity of downstream signaling. Moreover, western blotting was conducted to verify the expression results. In the animal model, the expression of ECM components and inflammatory genes was significantly upregulated. The expression of IL-6 was increased at both the mRNA level and the protein level in BOO rats. In vitro, hydrostatic pressure, and mechanical stretching both promoted MMP7 and MMP11 expression. Additionally, downregulation of collagen III occurred in both the hydrostatic pressure group and the mechanical stretch group. However, the expression of fibronectin exhibited opposing patterns between the hydrostatic pressure and mechanical stretch groups. The application of targeted siRNA transfection and an inhibitor (SC144) that targeted IL-6 significantly reversed the changes in MMP7 and MMP11 under mechanical stress and partially increased the expression of collagen III and fibronectin. In summary, IL-6 participated in the ECM remodeling of HBSMCs under mechanical stress, indicating that IL-6 may play an essential role in BOO.

A possible mechanism underlying mood disorders associated with LUTS: Chronic bladder outlet obstruction causes NLRP3‐dependent inflammation in the hippocampus and depressive behavior in rats

Reports link urinary dysfunction and mood disorders, such as depression, but a causative mechanism has never been postulated. Contemporary discoveries demonstrate a local inflammatory response in peripheral organs can trigger inflammation in the brain, particularly the hippocampus, mediated through the NLRP3 inflammasome. Critically, central inflammation causes depressive behavior. Since bladder outlet obstruction (BOO) evokes a local inflammatory response in the bladder, we hypothesize it will induce NLRP3-dependent inflammation in the hippocampus and depressive behavior. There were four groups of rats: control, sham, BOO, or BOO + glyburide (an NLRP3 inhibitor). BOO was created by urethral ligation over a 1 mm catheter. Sham was tied loosely. Glyburide was provided by slow-release pellet (subcutaneous 50 mg, 21 day, replaced as needed). Rats were analyzed 12 weeks post-op for: hippocampal inflammation, microglial density, neurogenesis, and depression symptoms (open field and sucrose preference). BOO elicited hippocampal inflammation, accompanied by an increase in activated microglia (22%) and a decrease in neurogenesis (35%), which was blocked by glyburide. In addition, BOO rats displayed anxiety (57% decrease in exploratory behavior in the open field assay) and anhedonia (21% decrease in sucrose preference), two symptoms of depression. Like inflammation, these symptoms were diminished by glyburide to levels not statistically significantly different from controls. BOO, a bladder-localized event, stimulates NLRP3-dependent inflammation in the rat hippocampus after 12 weeks and this inflammation causes depressive behavior. This is the first mechanistic explanation of the link between BOO and depression and provides evidence for a distinct bladder-brain axis.

Effects of 1% lidocaine instillation on overactive bladder induced by bladder outlet obstruction in rats

Lidocaine is a common local anesthetic and antiarrhythmic drug that acts via the local anesthetic effect of blocking voltage-gated sodium channels in peripheral neurons. To evaluate lidocaine as a therapeutic agent, we investigated optimal concentrations and effects of intravesical lidocaine instillation in a bladder outlet obstruction (BOO)-induced rat model of overactive bladder (OAB). To determine the therapeutic dosage of lidocaine, 16 female Sprague-Dawley (SD) rats (mean weight = 200 ± 20 g) were divided into four treatment groups: those receiving saline, 0.5% lidocaine, 1% lidocaine, and 2% lidocaine (n = 4 per group). Twenty-four additional SD rats were divided into two groups to investigate the effect of 1% lidocaine treatment in rats with BOO and normal rats (n = 12 per group). Cystometry was performed by infusing physiological saline and lidocaine into the bladder at a slow infusion rate (0.04 mL/min). Cystometric parameters were analyzed using PowerLab®. The expression of c-Fos, a protein expressed by C-fibers in the spinal cord (L6), was investigated via western blotting. Among the test lidocaine doses, only 1% lidocaine increased the intercontraction interval (ICI) (control mean = 500.56 ± 24.4 s; treatment mean = 641.0 ± 49.3 s; p < .01) without changes in threshold pressure and basal pressure. In the BOO-induced OAB group, the ICI increased significantly after instillation of 1% lidocaine (control mean = 135.8 ± 12.87 s; OAB-group mean = 274.2 ± 33.21 s; p < .01). Detrusor overactivity and non-voiding contraction were observed in the control group but not in rats with BOO after lidocaine instillation. The expression of c-Fos in C-fibers in the spinal cord (L6) decreased significantly after 1% lidocaine treatment in rats with BOO. Intravesical instillation of 1% lidocaine improves cystometric parameters without deterioration of contractility by blocking excessive C-fiber activity in the rat model of BOO-induced OAB. Therefore, instillation of 1% lidocaine has minimal effects on normal nerves while blocking nerves that contribute to OAB. Our findings suggest that intravesical instillation of 1% lidocaine is a useful treatment for OAB.

Long-term tadalafil administration can prevent functional and structural changes of the urinary bladder in male rats with partial bladder outlet obstruction.

There have been few reports on whether long-term oral phosphodiesterase 5 inhibitor administration can ameliorate bladder changes due to bladder outlet obstruction (BOO). Therefore, we clarified the chronological changes of the bladder using male BOO rats and evaluated the effects of tadalafil on these changes. Eight-week-old male Sprague-Dawley rats were used. BOO was created by placing a polyethylene catheter around the urethra. Then, the rats were orally treated with a vehicle, or tadalafil 2 or 10 mg/kg until each evaluation period. Cystometric measurements were performed and the degree of fibrosis in the smooth muscle layer was evaluated at 2, 4, and 16 weeks. In BOO rats, a significant increase in the number of non-voiding contractions (NVCs) and a shortened intercontraction interval (ICI) were observed in the earlier phase (2 and 4 weeks) compared to Sham rats. In the chronic phase (16 weeks), markedly increased residual urine volume and an extended ICI were observed accompanied by enhanced smooth muscle fibrosis. These results indicated that the bladder in BOO rats represented the overactive phenotype in the earlier phase and changed into the underactive phenotype in the chronic phase. Even in Sham rats, an increased number of NVCs and enhanced fibrosis were observed with time. Tadalafil administration significantly prevented these bladder changes in both BOO and Sham rats. Long-term oral administration of tadalafil can prevent functional and histological changes in the BOO rat bladder. This agent is also effective for the bladder functional change even in non-obstructed rats.

Blueberry Prevents the Bladder Dysfunction in Bladder Outlet Obstruction Rats by Attenuating Oxidative Stress and Suppressing Bladder Remodeling.

Various berries demonstrate antioxidant activity, and this effect is expected to prevent chronic diseases. We examined whether a diet containing blueberry powder could prevent the development of bladder dysfunction secondary to bladder outlet obstruction (BOO). Eighteen 8-week-old male Sprague-Dawley rats were randomly divided into three groups: Sham (sham operated + normal diet), N-BOO (BOO operated + normal diet) and B-BOO (BOO operated + blueberry diet). Four weeks after BOO surgery, the N-BOO group developed bladder dysfunction with detrusor overactivity. The B-BOO group showed significantly improved micturition volume and micturition interval. The urinary levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) were measured as oxidative stress markers. In the N-BOO group, 8-OHdG increased 1.6-fold and MDA increased 1.3-fold at 4 weeks after surgery, whereas the increase in 8-OHdG was significantly reduced by 1.1-fold, despite a similar increase in MDA, in the B-BOO group. Bladder remodeling was confirmed due to bladder hypertrophy, fibrosis and increased connexin43 expression in the N-BOO group, but these histological changes were reduced in the B-BOO group. The intake of blueberries prevented the development of bladder dysfunction secondary to BOO. This effect seems to be related to antioxidation and the inhibition of bladder remodeling.

α1 -Blocker inhibits non-voiding contractions and decreases the level of intravesical prostaglandinE2 in rats with partial bladder outlet obstruction.

To elucidate the mechanism of action of the α1 -blocker, naftopidil, in partial bladder outlet obstruction animals, by studying non-voiding contractions, and the levels of mediators were measured with resiniferatoxin treatment. A total of 35 female Wistar rats were randomly divided into a sham or bladder outlet obstruction group, and rats in each group were given vehicle or resiniferatoxin. Incomplete urethral ligation was applied to the bladder outlet obstruction group. After cystometry, the intravesical level of prostaglandinE2 and adenosine 5'-triphosphate was measured in the instilled perfusate collected. Naftopidil was given at the time of cystometry. In bladder outlet obstruction rats, non-voiding contractions, bladder capacity, and the intravesical levels of prostaglandinE2 and adenosine 5'-triphosphate were markedly increased compared with sham rats. Naftopidil decreased non-voiding contractions, enlarged the bladder capacity, and decreased the intravesical levels of prostaglandinE2 and adenosine 5'-triphosphate. Resiniferatoxin enhanced non-voiding contractions. The effects of naftopidil on non-voiding contractions and the intravesical level of prostaglandin E2 , but not adenosine 5'-triphosphate, were tolerant to resiniferatoxin. In bladder outlet obstruction rats, one cause of generation of non-voiding contractions might be bladder wall distension, but not transient receptor potential cation channelV1. The increase in intravesical prostaglandinE2 might also be associated with the generation of non-voiding contractions. Naftopidil inhibits the increase in non-voiding contractions and decreases the intravesical level of prostaglandinE2 , which are independent of transient receptor potential cation channelV1.

Effect of Sulforaphane on Bladder Compliance in a Rat Model of Partial Bladder Outlet Obstruction

Aims To investigate the effect of Nrf2 activator sulforaphane (SFN) on bladder compliance and the underlying mechanisms in a rat model of partial bladder outlet obstruction (BOO). Methods Male 8-week-old Sprague-Dawley rats were divided into three groups. BOO rats were given daily 0.5 mg/kg sulforaphane (BOO+SFN) or vehicle (BOO) intraperitoneally for 4 weeks, while sham-operated rats were treated with vehicle (Sham). Bladder compliance, histological alteration, and collagen deposition were evaluated. The expression levels of collagen I, collagen III, MMP-1, and TIMP-1 were measured by immunohistochemistry and western blotting. Results BOO led to a significant decrease in bladder compliance. The change was partially restored by SFN treatment. The expression of MMP-1 was significantly decreased accompanying with increased TIMP-1 expression in BOO rats compared with that in Sham rats, which was ameliorated by SFN treatment. Moreover, the increased collagen I/collagen III ratio in the BOO group was reversed by SFN treatment. Conclusions Sulforaphane suppressed collagen deposition by regulating the MMP-1 and TIMP-1 expression and decreasing the collagen I/III expression ratio in BOO rats and improved bladder compliance.

Bladder decompensation and reduction in nerve density in a rat model of chronic bladder outlet obstruction are attenuated with the NLRP3 inhibitor glyburide.

Bladder outlet obstruction (BOO) leads to progressive voiding dysfunction. Acutely, obstruction triggers inflammation that drives bladder dysfunction. Over time, inflammation leads to decreased bladder nerve density and increased fibrosis, responsible for eventual decompensation and irreversibility. We have previously shown that BOO triggers inflammation, reduced bladder nerve density and increased fibrosis via activation of the NLRP3 inflammasome in an acutely obstructed (12-day) rat model. However, as BOO progresses, the bladder may become decompensated with an increase in postvoid residual volume and decreased voiding efficiency. Currently, we have examined rat bladder function and nerve densities after chronic BOO to determine whether NLRP3 plays a role in the decompensation at this stage. Four groups were examined: control, sham-operated, BOO, or BOO+gly (glyburide; an NLRP3 inhibitor). After 42 days, bladder weight, inflammation (Evans blue), urodynamics, and nerve density were measured. BOO greatly enhanced bladder weights and inflammation, while inflammation was prevented by glyburide. Voiding pressures were increased, and flow rates decreased in BOO and BOO+gly groups, demonstrating physical obstruction. No difference in frequency or voided volume was detected. However, postvoid residual volumes were greatly increased in BOO rats while BOO+gly rats were not different than controls. Moreover, there was a dramatic decrease in voiding efficiency in the chronic BOO rats, which was prevented with glyburide treatment. Finally, a reduction in nerve density was apparent with BOO and attenuated with glyburide. Together the results suggest a critical role for NLRP3 in mediating bladder decompensation and nerve density during chronic BOO.

Epigallocatechin Gallate Attenuates Bladder Dysfunction via Suppression of Oxidative Stress in a Rat Model of Partial Bladder Outlet Obstruction.

Purpose To investigate the protective effect of epigallocatechin gallate (EGCG), a green tea extract, and its underlying mechanism on bladder dysfunction in a rat model of bladder outlet obstruction (BOO). Materials and Methods Sprague-Dawley rats of BOO were surgically induced and followed by treatment with EGCG (5 mg/kg/day) or saline (control) via intraperitoneal injection. Cystometry was performed on four weeks postoperatively in conscious rats. H&E, Masson trichrome, and TUNEL staining were performed to observe tissue alterations. Oxidative stress markers were measured, and protein expression of Nrf2-ARE pathway was examined by immunohistochemistry and Western blotting. Results Our data showed that EGCG could increase the peak voiding pressure and bladder compliance and prolong micturition interval of BOO rats compared with control and finally reduce the frequency of urinary. EGCG could ameliorate the increase of collagen fibers and ROS induced by obstruction and increase the activity of SOD, GSH-Px, and CAT. The level of cell apoptosis was decreased in BOO rats treated with EGCG compared with control, and caspase-3 expression was reduced as well. Moreover, EGCG could activate the Nrf2 expression with elevation of its target antioxidant proteins. Conclusions EGCG alleviates BOO-induced bladder dysfunction via suppression of oxidative stress and activation of the protein expression of Nrf2-ARE pathway.